TDA3681TH

Multiple voltage regulator with switch and ignition buffer

GENERAL DESCRIPTION

The TDA3681 is a multiple output voltage regulator with a power switch and an ignition buffer. It is intended for use in car radios with or without a microcontroller. The TDA3681 contains the following:

• Four fixed voltage regulators with a foldback current protection regulators 1, 2, 3 and 4. Regulator 2, which is intended to supply a microcontroller, also operates during load dump and thermal shutdown

• Regulators 3 and 4 have a second supply pin that can be connected to a lower supply voltage >6.5 V to reduce the power dissipation

• A power switch with protection, operated by a control input

• Reset and hold outputs that can be used to interface with the microcontroller; the reset signal can be used to call up the microcontroller

• Both supply pins can withstand load dump pulses and negative supply voltages

• Regulator 2, which is in regulation at a backup voltage above 6.5 V

• A provision for the use of a reserve supply capacitor that will hold enough energy for regulator 2 5 V continuous to allow a microcontroller to prepare for loss of voltage

• An ignition input Schmitt trigger with push-pull output stage.